Grinding machine



Jan. 4, 1944.

E. A. HALL ETAL GRINDING MACHINE Filed Jan. 19, 1943 2 Sheets- Sheet 1TIE-2* Y? l I 17% 35 Y yaw 3: IIIHIHI v l L zag Z 7? g5 h \l I: 5/ H Q1l Y1 L49 50 "7' fqzvzs'T A. ZZ ILL 14 4755 27" 5 EEI/JEMM Jan. 4, 1944.E. A. HALL ETAL GRINDING MACHINE Filed Jan. 19, 1943 2 Sheets-Sheet 2 Wmmr E .5 A5 v T M; W

Patented Jan. 4, 1944 GRINDING MACHINE Ernest A. Hall and Robert S.Beverlin, Toledo, Ohio, assignors to The Hall Manufacturing Company,Toledo, Ohio, a corporation of Ohio Application January 19, 1943, SerialNo. 472,870

12 Claims.

This invention relates primarily to eccentric valve seat grinders, andparticularly to improvements on those of the type shown in U. S. LettersPatent No. 2,116,498, wherein the device is intended more particularlybut not necessarily for use in grinding machines of the multiple spindletype.

In the device illustrated. in said patent, the drive or body shaft andthe grinding wheel carrying spindle are each divided into universallyjointed inner and outer sections, and the means which communicateseccentric movement to the grinding wheel around the pilot axis isincluded in part in the inner shaft section so that rotation of theshaft imparts revoluble movements to an eccentric portion of the upperspindle section relative to the shaft axis. This is found objectionablein many cases of use of the device in connection with multiple spindletype machines and also in the individual use of the devices.

An object of the present invention is to obviate said objections byproviding a device of the type and character shown in said patentwherein the means for imparting eccentric movements to the grindingwheel, or other tool, about the pilot axis is confined to the outershaft and spindle sections, thereby permitting the inner sections of thetwo parts to remain stationary during operation so far as any revolubleor eccentric movement thereof is concerned.

Other objects and advantages of the invention will be apparent from thefollowing detailed description, and from the accompanying drawings, inwhich- Figure 1 is a central longitudinal section, with parts in fulland parts broken away, of a device embodying the invention; Fig. 2 is anenlarged elevation, partly in central section, of the joint portion ofthe shaft member; Figs. 3, 4, 5 and 6 are perspective views of severalof the joint members of the shaft; Fig. '7 is a cross-section on theline 1-1 in Fig. 1; Fig. 8 is a side elevation of the flexible drivejoint portion of the spindle; Fig. 9 is a detail showing a differentmeans for connecting the shaft and pilot, with their axes in inclinedrelation, and Fig. 10 illustrates the use of the device for flat seatgrinding.

Referring to the drawings, I designates a section of an engine cylinderblock, 2 a valve seat in said block, which may be either flat ortapered, 3 a valve stem guide, 4 a pilot mounted in said guide andprojecting at its upper end through and above the seat, and 5 a grindingwheel in grinding relation to the valve seat.

The means embodying the invention includes a center shaft or body memberA, which comprises an upper section 6 and a lower section 1, and alsoincludes a grinding wheel driving spindle 8 mounted on said shaft andwhich likewise comprises an upper section 8 and a lower section 9mounted, respectively, on the shaft sections 5 and i. The shaft andspindle sections are connected together to have respective drivingcoaction and at the same time to permit the lower sections 1 and 9 tohave both universal angular or tilting and lateral sliding movementswith respect to the upper sections, whereby to permit an associatedgrinding means to accommodate itself to an out-of-true variance withinlimits of a valve seat to be ground and an associated guide pilot.

The upper section B of the shaft A is journaled in any suitablestationary part It of the associated grinding machine if used inconnection with such a machine, and is driven from its upper end in anysuitable manner, not shown. The shaft section 8 is provided in its lowerend, or that adjacent to the section I, with a longitudinally extendingbore 12 which is concentric to the axis of the section B.

A tubular plug I6 is threaded into the lower end of the bore l2 andcarries at its outer end a drive coupling member ll of tubular form, theupper or inner end of which is inwardly flanged over a shoulderedenlargement on said plug, while its lower or outer end is outwardlyflanged and threaded in the upper end of a sleeve It, the lower end ofsuch sleeve being extended a distance below the member I1 and providedwith an inwardly extending annular flange I9. A lock nut 23 threads onthe member ll above its lower end flange and is adapted to haveengagement with the adjacent end of the sleeve E8 to lock the members I1and H3 in assembled relation. The member ll, which is driven by theshaft section 6 through a key Il forms one member of a drive couplingjoint, in the present instance of the Oldham type, disposed between theshaft sections 6 and I. The sleeve I8 serves as a housing part aroundsuch coupling.

The adjacent ends of the shaft sections 6 and I are spaced to permit thepositioning of said drive coupling therebetween, and a member 2| of thiscoupling is mounted on the inner end of the shaft section I and heldthereto by a lock nut 22. The member 2| is of sleeve-form with its lowerend restricted for clamping to the shaft section I and with its free endprojected into the sleeve l8 and outwardly flanged to loosely engageover the sleeve flange iii in a manner to permit limited relativerocking and lateral shifting movements thereof. A floating coupling ring23 is interopsed between the spaced ends of the members i? and El andhas alternatel disposed lugs at opposite sides thereof, as shown in Fig.4, which enter respective notches in the ends of said coupling members.t is thus apparent that the coupling connection between the shaftsections ii and l imparts rotation from one to the other and at the sametime permits the outer section 7 to have not only angular or rockingmovements relative to the section 5, but also to have lateral bodilyshifting movements relative to such section so that the axis of onesection may be moved out or register with that of the other section.This enables the shaft section 1, which is intended to receive and havecentering engagement with a pilot, to accommodate itself to the positionof such pilot which may be tilted with respect to the axis of the shaftsection 6, or may be positioned so that its axis is out of coinciding orintersecting relation to the axis of the section 6, or both of suchconditions may be present.

The spacing means for the inner ends of the two shaft sections 8 and iincludes a half spherical joint member 26 which has its sphericalsurface facing outwardly or toward the shaft section 1 and seating onthe internal spherical face of a ring 2? mounted on the inner end of theshaft section '5. This spacing means also includes a flat disk member 28which seats at one side in a concentric recess in the adjacent end ofthe coupling member I? and at its opposite side on the fiat surface ofthe spherica1 joint member 26. It is thus apparent that the shaftsections may have relative angular or rocking movements about an axisconcentric to the half spherical member 2% and may also have relativetransverse shifting movements to place their axes into or out ofregistering relation by the transverse sliding movements of the jointmembers 26 and 28, one on the other.

The shaft section I, which is hollow, has a busing 3i) threaded into itsupper or inner end and projected a sufficient distance above the innerend of the shaft section 7 to enter and center a lock washer ti on theshaft section end. This Washer has spurs extending therefrom intonotches in the adjacent side of the lock nut 22. The spherical ring seat2! rests on this Washer. The bushing 3B is internall threaded to receiveand form an anchor for a threaded stem 3%, which stem projects upwardfrom the bushing through registering enlarged openings in the jointmembers and 28. The stem 34 extends through the lock washer 3i and hasflattened sides in coaction therewith to prevent a relative turningthereof. A link 35 is engaged at its lower or outer end to the upper orfree end of the stem 34 and extends up through the tubular plug 15 andinto the inner end portion of the bore i2 where it is attached to aplunger St in said bore. A coiled expansion spring 31 is disposed in thebore I2 between the plunger 35 and adjacent end of the plug it andexerts an upward pressure on the link 35 and stem 35 to hold the shaftsection l up in proper relation to the shaft section 6 and to hold thejoint parts 25 and 28 to their respective seats and in close slidingrelation to each other. It is thus apparent that the shaft section I isdriven by the shaft section 6 through the intermediate joint, and thatthe section I is permitted to not onl have universal rocking or angularmovements relative to the se tion 5, but also is permitted to have atransverse shifting movement relative to such section due to the slidingcoaction of the joint members and 2% and the manner of engagement of theOidhain joint members ll, 2! and 23, whereby the section i may assumeany desired position within predetermined limits to accommodate the axisof the pilot receiving bore 4!? to the fixed axis of the pilot 4irrespective of the position of the axis of the shaft section 6.

The drive section 8 of the spindle B is mounted concentrically on theshaft section 6 on upper and lower sets of ball bearings it and 55,respectively, which are held in spaced relation on the shaft section bya bushing ll interposed between the outer races thereof and mounted inthe spindle section 8. The upper end of the spindle section 8, in thepresent instance, is shouldered over the outer race of the upper ballset 45, and its lower end, below the ball set dd, is enlarged to form ahousing 48 to freely receive the joint members between the shaftsections 5 and l. A ring 49 threads into the upper or inner end portionof said enlargement in engagement with the adjacent end of the outerrace of the ball set 36 in opposition to the bushing 41, and this ringis internally notched to facilitate turning by use of a suitable tool.

The outer spindle section 9 is rotatably mounted on the shaft section "Ion inner and outer sets of ball bearings 59 and 5! which are concentricto the axis of longitudinal center of the shaft section and are spacedapart by a sleeve 52 mounted on the shaft section, which has its ends inengagement with the inner race rings of the respective bearings. Ashoulder 53 on the shaft section I engages the inner ring of the outerball bearing set 5! in opposition to the sleeve The spindle section 9shoulders over the outer race ring of the ball bearing set 5i? and hasits outer end projecting beyond the ball bearing set 5! and threaded toreceive the hub 55 of the grinding wheel 5.

The adjacent end portions of the spindle sections 8 and 9 are formed, inthe present instance, with outwardly projecting annular flanges 55 and5?, respectively, and the flange 5! has two drive pi is 58 projectingtherefrom toward the other flange, one at each side of its axis. Asimilar pair of pins 59 project from the flange 56 toward the flange 51at opposite sides of and in spaced relation to each pin 58. Each pin 59of a pair is yieldingly connected to the adjacent pin 58 by a respectivecoiled contractile spring 8%, the tension of which springs issubstantially the same so that the pins 58 are normally held in centeredrelation with respect to the associated pins 59. This provides afloating connection between the two sections and permits a yieldingdriving of one spindle section by the other and also allows for anyrelative tilting or adjusting movement of one section relative to theother. In addition to the yielding driving connection between thespindle sections just described, the section 3 has drive pins 5!projecting from its flange 56 at. each side of its axis and enteringrespective sockets 82 in the flange said sockets being larger incross-section than the pins iii, so that positive driving action doesnot take place until the pins have moved a distance sufficient to takeup any lost motion space between them and the socket walls, the pinsbeing normally held in neutral position within the sockets by the actionof the springs 65. It is thus apparent that .while a positive drivingaction may take place between the pins 6| and the lower spindle section9, the shock of the initial engagement of the pins with the socket Wallsof the section is absorbed or lessened to a considerable extent by thesprings 60 and also that the drive normally is through such springsunless considerable resistance is encountered.

The spindle B is intended to be driven at high speed, in the presentinstance, through a spur gear 65 on its upper end, from any suitabledrive means (not shown). This gives a high speed grinding action to thegrinding wheel 5. The speed of driving of the shaft is slow so that inthe case of eccentric grinding for which the present device is adapted,as hereinafter described, the point of contact of the grinding wheelwith the valve seat is caused to progressively travel around the seatduring the grinding action, as well understood in the art.

In order to adapt the present device for eccentric grinding, the shaftsection 1, in the present instance, has the spindle receiving portion 48of its bore disposed with its axis inclined slightly with respect to theaxis of the shaft section with the point of intersection of the two axescoinciding substantially with the center of the spherical joint members28 and 21, such point being indicated at c in Fig. 1. The divergence ofthe two axes is slight, as will be noted by the dotted axial lines a andb in Fig. 1. This divergence is sufiicient, however, to slightly tiltthe grinding wheel with respect to the valve seat and to cause it tohave grinding coaction with one side only of the seat, which point ofengagement progresses therearound as the shaft is rotated. It is thusapparent that by mounting the wheel carrying spindle section 9 on theshaft section 1 in concentric relation thereto, and by making thespindle receiving bore of the shaft section tapered as described withrespect to the wheel axis, the advantages of the eccentric mountingdisclosed in said former Patent 2,116,498 are obtained as well as someadditional advantages not possible by such former construction. Theadditional advantages reside primarily in having the eccentric movemententirely restricted to the outer section of the device and in disposingthe axis of rotation of the grinding wheel at a slight angle to thepilot axis. The importance of this latter feature is to permit a greaterrange of use of the device in connection with the grinding of valveseats of different characters and tapers. For instance, in the use ofthe device of said former patent, where the axes of the pilot andgrinding wheel are parallel, it is found impracticable to grind a flatvalve seat, whereas with the present arrangement the inclination of thewheel axis to that of the pilot permits the grinding of a flat valveseat, as shown in Fig. 10.

In the use of a grinding device embodying the present invention, andparticularly when used in connection with a multiple spindle grindingmachine, the lower shaft and spindle sections of the respective devicesare mounted down over the respective guide pilots of the work and saidlower sections of each device are permitted to adjust themselves to theparticular pilot with which associated and, due to the jointedconnection between the upper and lower sections of the device, withoutdisturbing or placing objectionable lateral strain on the upper drivingsections of the device. At the same time, the lower shaft and spindlesections of each device are positioned with their common axis inslightly inclined or diverging relation to the axis of the coactingpilot with the point of intersection of the diverging axes falling atapproximately the pivotal center of the lower or adjustable section ofthe device. It is apparent that the driving of the shaft at a low speedwhile the grinding wheel is driven at a high speed causes the point ofgrinding engagement of the wheel with the valve seat, which is at oneside only of the wheel axis, to progressively travel entirely around theseat so that uniform grinding is effected.

While the device shown has been particularly described for use inconnection with a multiple spindle grinding machine, it will beunderstood that its use is not limited to grinding machines, andparticularly valve seat grinders, but may be used in any connection forwhich it may be adapted and also that the device may be used separatelyfrom such a machine and as an individual unit in either grinding orother operations for which it may be adapted.

It will also be understood that while the sections of the shaft A andspindle B for convenience have been referred to as upper and lowersections, inasmuch as the devices are usually used above the work, it isnot intended or desired by such description to restrict the device touse above the work. The upper and lower shaft and spindle sections alsomay be considered as inner and outer sections, respectively, but thisterminology is not used in the specification, as it tends to causeconfusion where reference is made to the inner and outer end portions ofthe respective parts.

In Fig. 9 the inclined feature of the axes of the tool shaft and workpilot, when in connected operating relation, is shown as effected by theprovision of a cylindrical sleeve 19 mounted either in an axial bore ofthe shaft section 1, or on the pilot 4 and having its pilot receivingbore inclined to give the desired inclination to said shaft sectionrelative to the pilot axis when the device is in operation. In somecases this form might be preferable to that shown in Fig. 1, as itobviates the necessity of providing an inclined bore in the shaftsection, which might be a more difficult and expensive operation thanproviding a sleeve 19 with an inclined bore. It will be understood thatthis feature comes within the terminology of the claims which call forthe outer shaft section as having provision for centering engagementwith a stationary guide pilot with the axes of said section and pilotdiverging from a point substantially concentric to the rocking center ofthe section.

While this invention is not limited to any specific construction,arrangement or form of the parts, it will be understood that it iscapable of numerous modifications and changes without departing from thespirit of the claims.

Having thus described our invention, what we claim as new and desire tosecure by United States Letters Patent is:

1. In a device of the class described, a rotatable shaft having innerand outer sections, an Oldham type of drive joint between said sectionspermitting universal rocking and predetermined relative lateral shiftingmovements of the sections, a spacing means for the inner ends of thesections including a spherical seat on the inner end of the outersection, a spherical member engaging said seat and having asubstantially flat opposing face, and a second member seating on thefiat face of said first member and laterally shiftable relative thereto,means tying the shaft sections together through said joint members, saidouter section having a pilot receiving socket therein which is inclinedto and intersects the axis of such section at a point adjacent to therocking center of said joint and diverges therefrom toward the outer endof such section, a spindle including inner and outer sections rotatablymounted respectively on said inner and outer shaft sections concentricto their axes, and a grinding Wheel carried by the outer end portion ofthe outer spindle section with its axis concentric to the shaft sectionaxis.

2. In a device or" the class described, a slow speed rotatable shafthaving separate inner and outer sections connected end to end forrelative universal movements to permit the outer section to shiftrelative to the inner section to accommodate itself to a guide pilot, ahigh speed spindle having inner drive and outer driven sectionsrotatably mounted on said inner and outer shaft sections, respectively,concentric to their axes and including a floating driving connectionbetween their adjacent ends, and a grinding wheel carried by the outerend portion of said outer spindle section concentric thereto, said outershaft section having a guide pilot receiving bore the axis of whichintersects the shaft section axis adjacent to the center of theconnection between the shaft sections and diverges therefrom outwardlyfrom said center toward the outer end of the outer shaft section.

3. In a device of the class described, a slow speed rotatable shafthaving inner and outer sections and including an end thrust jointbetween said sections having a spherical concave seat on the outersection and a transverse sliding seat on the inner section together witha tying means between the sections, and also including a drive jointbetween the sections outside said end. thrust joint permitting relativeuniversal rocking and transverse shifting movements of the sections,said outer section having a bore in its outer end for receiving astationary work pilot with the axis of said bore inclined to andintersecting the axis of the section at a point substantially coincidingwith the center of the spherical joint between the sections with theoutward divergence of the axes toward the outer end of said outersection, a high speed spindle mounted on said shaft having inner andouter sections driven one from the other through a floating joint andmounted respectively on the inner and outer shaft sections concentric totheir axes, and a grinding wheel carried by the outer spindle sectionconcentric to its axis and adjacent to the outer end of said outer shaftsection.

a. In combination, a valve seat grinding tool and a pilot for holdingthe tool in operative relation to a valve seat to be ground, said toolincluding a shaft and a grinding wheel carrying spindle mounted one onthe other for relative concentric rotation and each having inner andouter sections jointed at their inner ends for relative universalrocking movements and. the outer shaft section and the pilot havinginterengaging connection in use with the turning axis of the outer shaftsection inclined to the pilot axis at approximately the joint center ofthe two shaft sections with the divergence of said axes away from saidcenter toward the outer end of the outer shaft section whereby the axisof the wheel carrying portion of the spindle has an orbital movementaround the pilot axis during grinding.

5. In a device of the class described, a tool carrying spindle havinginner and outer sections driven one from the other and connected forrelative universal rocking movements, 2. tool carried by said outerspindle section at its outer end relative to the rocking connection ofthe sections, said outer section having provision at its tool carryingend for centering engagement with a stationary guide pilot about whichthe section may turn with the axes of said section and pilot divergingoutwardly from a point substantially concentric to the rocking center ofthe sections toward the tool carrying end of the section whereby thedegree of eccentric throw of said outer section relative to the pilotaxis increases outwardly from such point toward its tool carrying end.

6. In a device of the class described, a spindle having an inner drivesection and an outer driven tool carrying section, a wheel like toolcarried by said outer section at its outer end, and a connection betweensaid sections including a universal rocking and universal transverseshifting joint enabling one section to be driven by the otherirrespective of any predetermined out-ofline relationship of the axes ofthe two sections, said outer section having provision for centeringengagement with a stationary guide pilot about which the section mayturn with the axes of said section and pilot diverging outwardly from apoint substantially concentric to the rocking center of the sectionstoward the tool carrying end of the outer section whereby the degree ofeccentric throw of said outer section relative to the pilot axisincreases outwardly from such point toward its tool carrying end.

7. In a device of the class described, a spindle having an inner drivingsection and an outer driven tool carrying section connected for relativeuniversal rocking movements, a tool on the outer end portion of saidouter section, and a guide part in said outer section having provisionfor receiving a guide pilot and to turn thereon with the axes of saidsection and pilot diverging outwardly from a point substantiallyconcentric to the rocking center of the section toward the tool carryingend of the section whereby the tool axis has an orbital movement aboutthe pilot axis when said guide part is turned.

8. In a device of the class described, a spindle divided into an innerdriving section and an outer driven section connected end to end forrelative universal rocking movements, a work treating tool on the outerend portion of the outer section, and means rotatable in said outersection and having provision for centering engagement with a guide pilotwith the axis of rotation of said means and that of the pilot divergingoutwardly from a point adjacent to the point of connection of thespindle section toward the tool carrying end of the outer sectionwhereby the tool axis has an orbital movement about the pilot axis whensaid means is rotated.

9. In a device of the class described, a spindle divided into an innerdriving section and an outer driven section connected for rotaryuniversal rocking movements, a grinding wheel carried by said outersection in outwardly spaced relation to its rocking connection, and arotatable shaft part concentric to and about which said outer sectionrotates and having in its outer end a pilot receiving bore with its axisdiverging outwardly from that of the shaft part at a point adjacent tothe inner end of the outer spindle section and toward the wheel carriedthereby whereby the grinding wheel axis has an orbital movement aboutthe axis of said bore when said shaft part is rotated.

10. In a device of the class described, a spindle divided into an innerdrive section and an outer driven section connected. for relativeuniversal rocking and other movements, a work treating tool carried bysaid outer section at its outer end, and a rotatable shaft partjournaled in said outer section With its axis of rotation concentric tothat of the outer spindle section, said shaft part having a work pilotreceiving bore extending inwardly from its outer end with its axisinclined to the axis of rotation of the part and intersecting the latteradjacent to the rocking center of the outer spindle section with thedivergence of said axes outwardly from a point substantially coincidentwith said rocking center and toward the tool carrying end of the outersection.

11. In a device of the class described, a spindle having inner and outersections driven one from the other and connected for predeterminedrocking and transverse shifting movements of the outer section relativeto the inner section, a grinding wheel carried by said outer section atits outer end, a shaft forming a concentric mount for each of saidsections and jointed between said sections for relative universalrocking and other movements, said shaft being rotatable at a speeddifferent from that of the spindle, the portion of the shaft carryingthe outer spindle section having a guide pilot bore extending thereinfrom its outer end with its axis slightly inclined to and intersectingthe axis of rotation of the outer spindle section at a point adjacent tothe rocking center of the shaft and spindle sections, the divergence ofthe axes being outwardly from said point toward the tool carrying end ofthe outer section.

12. In a device of the class described, a rotatable shaft having innerand outer sections connected for relative universal rocking movements, aspindle having jointed inner and outer sections rotatably mountedrespectively on the inner and outer shaft sections, a grinding Wheelcarried by the outer spindle section at its outer end, said outer shaftsection having a bore extending inwardly from its outer end for closelyreceiving a stationary guide pilot, said bore having its axis inclinedto and intersecting the axis of rotation of the outer spindle part at apoint coinciding substantially with the rocking center of the shaftsections, the divergence of the axes being outward from such pointtoward the Wheel carrying end of the outer spindle section.

ERNEST A. HALL. ROBERT S. BEVERLIN.

